The drive from Dublin to the Border at Fermanagh is, on first impression, difficult to separate from most other road journeys through rural Ireland.

For a few brief miles around the Border however, the landscape is transformed: heavy industry here, hotels there, huge office developments on the side of that hill. It is as if the air around the Cavan/Fermanagh frontier is a shade richer than in neighbouring parts.

There is, of course, a theme to this little belt of wealth, with the name "Quinn" appearing more often than not on some aspect of the development. Even the roads in the area appear to be dominated by the name, with Quinn lorries usually within sight on parts of the winding route.

The change begins on the edge of Cavan town, with the appearance of the Hotel Kilmore, one of seven such properties owned by Mr Seán Quinn's Quinn Group.

Tucked in behind the hotel is an office park that began life as one building to house the start-up phase of Quinn Direct insurance in 1996.

A few miles further on, the hulk of a massive cement plant appears on the horizon, strangely close to Mr Quinn's flagship 159-room hotel, the Slieve Russell. Larger houses also appear here, presumably standing testament to the purest form of trickle-down economics.

And, of course, the visible Border developments are only part of the story: there are hotels in England, seven pubs in various locations, glass plants, insulation operations and, most relevant this week, a financial services arm that has its sights on ambitious growth.

The acquisition (subject to regulatory approval) of a 20 per cent stake in Dublin stockbroker NCB is merely the latest step in Mr Quinn's apparent plan for world domination.

In a release accompanying the surprise news of his involvement in NCB, it emerged that the Quinn Group would make a pre-tax profit of more than €150 million this year on turnover of some €650 million. That would make Quinn Group close to double the size of Heiton and about 12 times the size of Gresham. No further details were on offer from the Fermanagh-based company, with the voluntary provision of even this snippet seen as uncharacteristically expansive.

Research in the Companies Offices of Dublin and Belfast bears more fruit, but again the hard numbers are a touch difficult to grasp. Quinn Group seems to be owned by another entity called Quinn Investments, with the most up-to-date figures available for this showing a pre-tax loss of some €38 million in 2000 on turnover of about €260 million.

At about the same time, Quinn Group owned 25 per cent of an unlimited company registered in the Republic called Arleview, which had net assets of about €52 million at the end of 2001. The remainder of Arleview was at this time owned by Irish-registered Aronmoon Ltd, which counted a Jersey-based entity apparently called after one of Mr Quinn's five children (the Ciara Quinn Settlement) as its only named shareholder.

Arleview, meanwhile, had a Dutch subsidiary called Quinn Investments BV which was simply described as an "investment company".

Confused? Well, perhaps the complications are to be expected. This is, after all, a privately owned entity that has nobody to please on the financial front apart from the private individuals who stand at its helm. And just for the record, Mr Quinn was said earlier this year to be mulling a restructuring of his affairs with a view to preparing for the trouble-free inheritance of his family.

NCB, for its part, is more than content with with the prospect of Quinn Financial Services as a strategic partner, with the company's Irish identity apparently a big hit with both the broker's clients and its employees.

In the context of the wider Quinn Group, the estimated €4 million due to be pumped into NCB, is small fry. It also looks meagre when placed beside the €8.5 million being invested in an expansion of Quinn Direct in Enniskillen, Co Fermanagh, and pales next to the €51.9 million offered by Quinn Group for the glass operations of Ardagh earlier this year.

That bid failed, but most of Mr Quinn's other efforts to make waves in the Irish business world have displayed an uncanny sense of timing and opportunity, while attracting serious scepticism from his numerous begrudgers.

His first big coup came in the late 1980s when he successfully entered the previously closed Irish cement market by simultaneously taking on the monolithic CRH and Blue Circle, and stealing an all-Ireland position.

The sceptics became even louder when Quinn Direct entered the picture, with the incumbent insurers hardly able to believe that their position was being challenged by a cement-maker from Fermanagh.

Doubts were again voiced when a move into glass came in the late 1990s, but again the investment was well judged, with Quinn Glass now the only container glass plant in Ireland.

By now, even the smallest twitch from the Quinn headquarters at Derrylin tends to gain respectful attention in the wider market.

A challenge to Kingspan's insulation operations with the construction of a new plant in Cavan was the most recent such newsmaker, with the merit of the move immediately appreciated rather than doubted.

History suggests that once the initial shock of the NCB move has quietened down, Mr Quinn's expansion into stockbroking will also win round the cynics - whether they like it or not.